Fixed vs. Adjustable-Rate Mortgages: Pros and Cons
How fixed-rate and adjustable-rate mortgages work, how ARM caps and indexes work, and how to decide which is right for you.
Choosing between a fixed-rate mortgage and an adjustable-rate mortgage (ARM) is one of the biggest decisions in financing a home. Each can be the right choice depending on your timeline and tolerance for risk.
How fixed-rate mortgages work
The interest rate is locked for the entire loan, usually 15 or 30 years. Your principal-and-interest payment never changes, though taxes and insurance in your escrow can. Fixed loans provide certainty, and if rates later drop, you can refinance.
How ARMs work
An ARM starts with a fixed rate for an introductory period, then adjusts on a schedule. A "5/6 ARM," for example, is fixed for five years and then adjusts every six months. After the fixed period, the new rate equals an index (most commonly SOFR, the Secured Overnight Financing Rate, for newer loans) plus a fixed margin set in your contract.
ARM caps
Caps limit how much the rate can change. They're often written as three numbers, such as 2/1/5: the first adjustment can't exceed 2 percentage points, each later adjustment can't exceed 1 point, and the rate can never rise more than 5 points above the starting rate. Always ask for the worst-case payment so you know you could handle it.
Pros and cons at a glance
| Fixed-rate | Adjustable-rate | |
|---|---|---|
| Initial rate | Usually higher | Often lower |
| Payment certainty | Complete | Only during fixed period |
| Best for | Long-term owners, budget certainty | Buyers likely to sell or refinance before adjustment |
| Main risk | Overpaying if rates fall (can refinance) | Payment shock if rates rise |
When an ARM can make sense
If you're confident you will sell or refinance before the fixed period ends, an ARM's lower initial rate can save real money. But remember that plans change, refinancing depends on qualifying again and on future rates, and home values can fall. Do not choose an ARM because you can only afford the home at the teaser rate.
The bottom line
For most buyers who plan to stay a long time, a fixed-rate loan offers peace of mind. For shorter horizons, an ARM may be worth considering, ideally with a long fixed period and conservative caps. Compare both using real Loan Estimates.
This article is for general educational purposes and is not financial, legal, or tax advice. See our disclaimer.